Surface-modified silicon carbide wafer as well as surface treatment method and application thereof

Abstract

The invention relates to a surface-modified silicon carbide wafer as well as a surface treatment method and application thereof, and the surface treatment method comprises the following steps: pretreating the silicon carbide wafer by adopting an acid solution, so that the surface roughness of the pretreated silicon carbide wafer is Ra, and the unit is nm; a fluorine-containing silane solution is adopted for carrying out a washing reaction on the pretreated silicon carbide wafer, the flow Q of the fluorine-containing silane solution is equal to-4.5 Ra < 2 > + 16.2 Ra + n, n is equal to-1.7 to-1.5, the unit is mL / min, and the goodness of fit is larger than or equal to 0.95. According to the surface treatment method, metal ion adsorption can be effectively blocked, the original performance of the silicon carbide wafer is not affected, the prepared surface-modified silicon carbide wafer is used for preparing a semiconductor device, the reliability and stability of the semiconductor device are improved, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor materials, in particular to a surface-modified silicon carbide wafer and a surface treatment method and application thereof. BACKGROUND

[0002] As a typical representative of the third generation of semiconductor materials, silicon carbide wafers have a wide application prospect in the fields of power devices and radio frequency devices due to their excellent characteristics such as high breakdown electric field strength, high electron mobility saturation speed, and high thermal conductivity. However, silicon carbide wafers are extremely susceptible to metal ion contamination during the manufacturing, processing, and device preparation processes. After the metal ions are adsorbed on the surface of the silicon carbide wafer, impurity energy levels are introduced, which changes the electrical properties of the semiconductor, leading to problems such as increased leakage current, reduced breakdown voltage, and poor stability of the device, which seriously affects the performance and yield of silicon carbide-based semiconductor devices.

[0003] Traditional methods for solving the problem of metal ion adsorption on the surface of silicon carbide wafers have many shortcomings. In terms of cleaning process optimization, traditional methods mainly use special cleaning reagents or cleaning processes to remove metal ions. For example, the traditional RCA cleaning method uses a mixed solution of hydrochloric acid (HCl) and hydrofluoric acid (HF) to treat the wafer, which can remove some metal ions and oxides, but this method has limitations. On the one hand, a large amount of chemical reagents are used in the cleaning process, which can easily cause environmental pollution, and the cost of treating the waste water after processing is high. On the other hand, the removal effect of stubborn organic matter and small particle contaminants is not good, and the cleaning process may cause some damage to the wafer surface, affecting the performance and quality of the wafer, and it is difficult to fundamentally prevent the re-adsorption of metal ions in the subsequent use process. Some studies attempt to form a passivation film on the wafer surface to solve the problem of metal ion adsorption. However, traditional passivation films are usually based on the by-products of the chemical reaction of the cleaning solution itself, or simple oxide film layers, which have limited chemical stability and barrier effect. For example, the oxide film formed on the surface of the silicon wafer by hydrogen peroxide can prevent particles from re-attaching to some extent, but it has insufficient long-term barrier capability for metal ions, and cannot meet the increasingly stringent requirements of semiconductor manufacturing. In addition, the adhesion of the passivation film to the silicon carbide wafer is weak, and in the subsequent complex semiconductor manufacturing processes (such as high temperature, etching, etc.), the film layer may fall off or be damaged, causing metal ions to be re-adsorbed on the wafer surface.

[0004] In the surface deposition technology, some studies attempt to deposit other materials on the surface of silicon carbide to improve the surface performance, but there are also problems. For example, when depositing other carbon-based materials or nitrides on the surface of silicon carbide, there is a problem that the deposition process is difficult to control accurately, which easily leads to uneven deposition of materials, and the formed film layer has many defects, not only cannot effectively block metal ions, but also may introduce new impurities. Moreover, the lattice matching degree between these materials and silicon carbide wafers is poor, and the stress generated due to the mismatch of the thermal expansion coefficient under high temperature process will cause the film layer to crack, peel off and other phenomena, affecting the performance of silicon carbide wafers and subsequent device manufacturing. At the same time, the existing surface deposition technology lacks effective means to solve the problems of impurity introduction and growth compatibility, further limiting its application in preventing metal ion adsorption on silicon carbide wafers.

[0005] Therefore, it is crucial to develop a surface treatment technology that can effectively block metal ion adsorption without affecting the original performance of silicon carbide wafers, and at the same time solve the problems of impurity introduction and growth compatibility. SUMMARY

[0006] Therefore, it is crucial to develop a surface treatment technology that can effectively block metal ion adsorption without affecting the original performance of silicon carbide wafers, and at the same time solve the problems of impurity introduction and growth compatibility.

[0007] A surface treatment method of a silicon carbide wafer, comprising the following steps:

[0008] The silicon carbide wafer is pretreated with an acid solution, so that the surface roughness of the pretreated silicon carbide wafer is Ra, unit: nm;

[0009] The pretreated silicon carbide wafer is washed with a fluorine-containing silane solution, wherein the flow rate Q of the fluorine-containing silane solution is -4.5Ra 2 +16.2Ra+n, n=-1.7 to-1.5, unit: mL / min, goodness of fit ≥0.95.

[0010] In one embodiment, the surface roughness Ra of the pretreated silicon carbide wafer is 0.5 nm to 2.0 nm.

[0011] In one embodiment, the mass concentration of fluorine-containing silane in the fluorine-containing silane solution is 0.1% to 1%.

[0012] In one embodiment, the fluorine-containing silane solution is selected from at least one of perfluorooctyltriethoxysilane solution and tridecafluorooctyltriethoxysilane solution.

[0013] In one embodiment, the temperature of the rinsing reaction is 20-50℃, and the time is 30-120s.

[0014] In one embodiment, the acid solution is selected from a hydrofluoric acid solution, and the mass concentration of the hydrofluoric acid in the hydrofluoric acid solution is 5-8%.

[0015] In one embodiment, the temperature of the pretreatment is 20-30℃, and the time is 10-60s.

[0016] In one embodiment, the silicon carbide wafer after the rinsing reaction is subjected to a photocuring treatment, and the wavelength of the photocuring treatment is 10-400nm, and the time is 30-45min.

[0017] A surface-modified silicon carbide wafer prepared by the surface treatment method of the silicon carbide wafer as described above, and the contact angle of the surface-modified silicon carbide wafer is greater than 110°.

[0018] Use of the surface-modified silicon carbide wafer as described above in the preparation of a semiconductor device.

[0019] The surface treatment method of the present application, which is different from the conventional preparation method, adopts a dynamic process chain, uses an acid solution to pre-control the surface roughness of the oxide layer of the silicon carbide wafer, creates micro-morphology conditions for uniform coverage of fluorine-containing silane, and dynamically adjusts the application rate of the fluorine-containing silane solution according to the specific quantitative relationship between the surface roughness Ra of the silicon carbide wafer and the flow rate Q of the fluorine-containing silane solution, so that the fluorine-containing silane forms a relatively uniform hydrophobic and anti-adhesion layer on the surface of the silicon carbide wafer, thereby effectively blocking the adsorption of metal ions on the surface of the silicon carbide wafer, and significantly improving the electrical performance of the silicon carbide wafer. The semiconductor device manufactured based on the silicon carbide wafer can increase the breakdown voltage by 15-20%, reduce the leakage current by 30-50%, greatly improve the reliability and stability of the device, and prolong the service life of the device. DETAILED DESCRIPTION

[0020] In order to facilitate the understanding of the present application, the present application will be described in more detail below. However, it should be understood that the present application can be realized in many different forms, and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the disclosure of the present application more thorough and comprehensive.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing specific embodiments or examples only and is not intended to be limiting. As used in this patent, the term "and / or" means any one of the items, or any combination of the items, listed after the term. In the present application, reference to a number interval, such as, for example, 1 to 10, is understood to be continuous, unless otherwise indicated, and includes the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Further, when a range is provided, it is intended to encompass every integer within the range, unless otherwise indicated. Additionally, when a plurality of ranges are provided, it is intended to encompass every combination of these ranges.

[0022] The present application provides a surface treatment method of silicon carbide wafer, comprising the following steps:

[0023] The silicon carbide wafer is pretreated by using an acid solution, so that the surface roughness of the pretreated silicon carbide wafer is Ra, nm;

[0024] The pretreated silicon carbide wafer is washed by using a fluorine-containing silane solution, wherein the flow rate Q of the fluorine-containing silane solution is =-4.5Ra+16.2Ra+n, n=-1.7 to-1.5, mL / min, and the goodness of fit is ≥0.95. 2 +16.2Ra+n, n=-1.7 to-1.5, mL / min, and the goodness of fit is ≥0.95.

[0025] The surface treatment method of the present application is different from the traditional preparation method, and a dynamic process chain is used to pre-control the surface roughness of the oxidation layer of the silicon carbide wafer by using an acid solution, to create micro-morphology conditions for uniform coverage of the fluorine-containing silane, and to dynamically adjust the application rate of the fluorine-containing silane solution according to the specific quantitative relationship between the surface roughness Ra of the silicon carbide wafer and the flow rate Q of the fluorine-containing silane solution, so that the fluorine-containing silane forms a relatively uniform hydrophobic and anti-adhesion layer on the surface of the silicon carbide wafer, thereby effectively blocking the adsorption of metal ions on the surface of the silicon carbide wafer, and further significantly improving the electrical performance of the silicon carbide wafer.

[0026] It should be noted that the present application does not limit the specific type and model of the silicon carbide wafer, and n-type or p-type can be used. The closer the goodness of fit is to 1, the better the model fitting effect is.

[0027] In an embodiment of the present application, the surface roughness Ra of the pretreated silicon carbide wafer is preferably 0.5 nm to 2.0 nm, which is more conducive to creating favorable micro-topography conditions for uniform coverage of the subsequent fluorine-containing silane on the wafer surface.

[0028] It can be understood that the surface roughness Ra of the pretreated silicon carbide wafer includes but is not limited to any one of 0.5 nm, 1.0 nm, 1.5 nm, 2.0 nm or a range value between any two of them.

[0029] In an embodiment of the present application, the acid solution is selected from a hydrofluoric acid solution, which is conducive to achieving selective etching, which is different from the overall etching in the traditional process. As a preferred, the mass concentration of hydrofluoric acid in the hydrofluoric acid solution is 5% to 8%, including but not limited to any one of 5%, 6%, 7%, 8% or a range value between any two of them.

[0030] In an embodiment of the present application, the temperature of the pretreatment is 20°C to 30°C, including but not limited to any one of 20°C, 22°C, 25°C, 27°C, 30°C or a range value between any two of them; the time is 10s to 60s, including but not limited to any one of 10s, 20s, 30s, 50s, 60s or a range value between any two of them.

[0031] It can be understood that when the mass concentration of hydrofluoric acid in the hydrofluoric acid solution and the temperature of the pretreatment are certain, different surface roughness Ra can be obtained by adjusting the pretreatment time, and the longer the pretreatment time, the greater the surface roughness Ra of the pretreated silicon carbide wafer.

[0032] In an embodiment of the present application, before the pretreatment step is performed, the silicon carbide wafer is preferably ultrasonically cleaned with deionized water and dried with nitrogen to remove surface impurities.

[0033] In an embodiment of the present application, after the pretreatment step is performed, the pretreated silicon carbide wafer is preferably rinsed with deionized water and dried with nitrogen to remove residual acid solution on the surface.

[0034] In the surface treatment method of the present application, the pretreated silicon carbide wafer is rinsed with a fluorine-containing silane solution having a specific flow rate Q, which has the following technical advantages:

[0035] First, there is a surface chemical reaction between the fluorine-containing silane solution and the silicon carbide wafer: There are usually a certain number of hydroxyl (-OH) groups on the surface of the silicon carbide wafer, which are formed due to exposure to air and water vapor. The fluorine-containing silane molecule structure contains silanol groups, which will undergo hydrolysis under appropriate conditions to generate silanol groups (-SiOH). These silanol groups can undergo dehydration condensation with the hydroxyl groups on the surface of silicon carbide to form stable Si-O-Si chemical bonds, thereby allowing the fluorine-containing silane to firmly adhere to the surface of silicon carbide. This chemical bonding effect is similar to a "anchoring" mechanism, allowing the fluorine-containing silane to form a stable covering layer on the surface of silicon carbide, which is beneficial to improving the binding stability between the fluorine-containing silane and silicon carbide.

[0036] Second, there is intermolecular interaction between the fluorine-containing silane solution and the silicon carbide wafer: Even without considering the formation of chemical bonds, there are also intermolecular interactions such as van der Waals forces between the fluorine-containing silane molecules and the surface of silicon carbide. The carbon-fluorine segment of the fluorine-containing silane molecule has low surface energy characteristics, although the intermolecular cohesion is weak, but there is a certain attractive force between the atoms on the surface of silicon carbide. When the fluorine-containing silane molecules approach the surface of silicon carbide, the van der Waals force causes the fluorine-containing silane to gather and arrange on the surface, allowing the fluorine-containing silane to spread uniformly on the surface of silicon carbide and form a continuous thin film, which plays an auxiliary role in the stable binding between the fluorine-containing silane and silicon carbide on a macroscopic structure.

[0037] Third, the fluorine-containing silane and the silicon carbide wafer have structural adaptability: The fluorine-containing silane molecule has a certain flexibility and deformability, and its carbon-fluorine segment and silane structure can adapt to the micro-topography and unevenness of the surface of silicon carbide to a certain extent. Even if there are atomic-level defects, steps or roughness on the surface of silicon carbide, the fluorine-containing silane molecules can adjust their structure to closely adhere to the surface, fill in the small depressions or protrusions, and form a relatively uniform covering layer, thereby exhibiting good binding effect on a macroscopic structure, similar to a "self-adaptive" fit, which makes up for the lack of lattice matching between the fluorine-containing silane and silicon carbide.

[0038] It should be noted that the relationship between the surface roughness Ra of the silicon carbide wafer and the flow rate Q of the fluorine-containing silane solution only involves quantity conversion, and does not involve unit conversion.

[0039] In an embodiment of the present application, the mass concentration of fluorine-containing silane in the fluorine-containing silane solution is 0.1% to 1%, including but not limited to any one of 0.1%, 0.2%, 0.5%, 0.8%, 1% or a range value between any two of them.

[0040] In an embodiment of the present application, the fluorine-containing silane solution is selected from at least one of perfluorooctyltriethoxysilane solution (FOTS) and tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane solution, preferably perfluorooctyltriethoxysilane solution.

[0041] It can be understood that the solvent in the fluorine-containing silane solution can be an organic solvent such as anhydrous toluene, and the present application does not limit this.

[0042] In an embodiment of the present application, the temperature of the rinsing reaction is 20℃ to 50℃, including but not limited to any one value or a range value between any two values of 20℃, 30℃, 40℃, 50℃; the time is 30s to 120s, including but not limited to any one value or a range value between any two values of 30s, 50s, 80s, 100s, 120s.

[0043] In an embodiment of the present application, after the rinsing reaction step, the silicon carbide wafer after the rinsing reaction is preferably rinsed with an organic solvent and dried in a nitrogen atmosphere to remove unreacted fluorine-containing silane on the surface.

[0044] In an embodiment of the present application, the silicon carbide wafer after the rinsing reaction is subjected to a photocuring treatment, which takes advantage of the wide band gap characteristics of silicon carbide to promote the cross-linking and curing of unreacted silane molecules, and is conducive to further improving the density of the surface modification coating.

[0045] In an embodiment of the present application, the wavelength of the photocuring treatment is 10nm to 400nm, including but not limited to any one value or a range value between any two values of 10nm, 50nm, 100nm, 200nm, 400nm; the time is 30min to 45min, including but not limited to any one value or a range value between any two values of 30min, 35min, 40min, 45min.

[0046] The present application provides a surface-modified silicon carbide wafer, which is prepared by the surface treatment method of the silicon carbide wafer as described above. The hydrophobic and anti-adhesion layer formed by the fluorine-containing silane on the surface of the silicon carbide wafer has extremely low surface energy, and metal ions are difficult to adhere to the surface. The fluorine atoms in the molecular structure of the fluorine-containing silane can provide a strong electron cloud shielding effect, reducing the interaction force between the surface and the metal ions, and physically blocking the adsorption of metal ions. At the same time, the hydrophobic and anti-adhesion layer can effectively prevent moisture and other impurities from remaining on the surface of the wafer, further reducing the possibility of metal ion adsorption.

[0047] Preferably, the contact angle of the surface-modified silicon carbide wafer is greater than 110°, including but not limited to any one value or a range value between any two values of 112°, 115°, 118°, 120°.

[0048] The application further provides application of the surface-modified silicon carbide wafer in the preparation of a semiconductor device.

[0049] The semiconductor device manufactured based on the silicon carbide wafer has a breakdown voltage increased by 15% to 20% and a leakage current reduced by 30% to 50%, thereby greatly improving the reliability and stability of the device and prolonging the service life of the device.

[0050] Hereinafter, the surface-modified silicon carbide wafer, the surface treatment method and the application thereof will be further described through the following specific examples. However, those skilled in the art will understand that the following examples are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. If no specific conditions are indicated in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If no manufacturer of the reagent or instrument is indicated, it is a conventional product that can be obtained by purchase on the market.

[0051] Example 1

[0052] The silicon carbide wafer (4 inches in size, n-type, 500 μm in thickness) was ultrasonically cleaned with deionized water for 10 min to remove the surface impurities, and then dried with nitrogen. The silicon carbide wafer was placed in an etching tank containing a hydrofluoric acid solution with a concentration of 5% for pretreatment, and the etching temperature was controlled at 25°C and the etching time was 10 s. After etching, the silicon carbide wafer was washed with deionized water for 5 min and dried with nitrogen, thereby obtaining a pretreated silicon carbide wafer.

[0053] The perfluorooctyltriethoxysilane was mixed with anhydrous toluene to prepare a fluorine-containing silane solution with a concentration of 0.5 wt% as a cleaning solution of a single wafer cleaning machine. The pretreated silicon carbide wafer was placed in the single wafer cleaning machine, and the temperature of the cleaning machine was set to room temperature and the brush pressure was a constant value (0.5 N according to the standard setting of the equipment). The silicon carbide wafer was washed with the fluorine-containing silane solution at a flow rate of 5.4 mL / min at 30°C for 60 min. After the treatment, the silicon carbide wafer was washed with anhydrous toluene for 30 s, and then dried in a nitrogen atmosphere.

[0054] The silicon carbide wafer after washing was subjected to photopolymerization treatment with ultraviolet light with a wavelength of 200 nm for 30 min, thereby obtaining a surface-modified silicon carbide wafer.

[0055] Example 2

[0056] The difference between Example 2 and Example 1 is that the etching time is 30 s and the fluorine-containing silane solution is washed at a flow rate of 11.3 mL / min.

[0057] Example 3

[0058] The difference between Example 3 and Example 1 is that the etching time is 60 s and the fluorine-containing silane solution is washed at a flow rate of 12.7 mL / min.

[0059] Example 4

[0060] The silicon carbide wafer (4 inches in size, n-type, 500 μm in thickness) was ultrasonically cleaned with deionized water for 10 min to remove surface impurities, and then dried with nitrogen. The silicon carbide wafer was placed in an etching tank containing a 8% hydrofluoric acid solution for pretreatment, and the etching temperature was controlled at 35°C for 10 s. After etching, the wafer was rinsed with deionized water for 5 min and dried with nitrogen to obtain a pretreated silicon carbide wafer.

[0061] The perfluorooctyltriethoxysilane was mixed with anhydrous toluene to prepare a 1 wt% fluorosilane solution, which was used as the cleaning solution of a single wafer cleaning machine. The pretreated silicon carbide wafer was placed in the single wafer cleaning machine, and the temperature of the machine was set at room temperature, and the brush pressure was a constant value (0.5 N according to the standard of the equipment). The wafer was rinsed with the fluorosilane solution at a rate of 8 mL / min at 40°C for 60 min. After the treatment, the wafer was rinsed with anhydrous toluene for 30 s, and then dried under a nitrogen atmosphere.

[0062] The rinsed silicon carbide wafer was subjected to photopolymerization treatment with ultraviolet light of a wavelength of 150 nm for 20 min to obtain a surface-modified silicon carbide wafer.

[0063] Comparative Example 1

[0064] Comparative Example 1 differs from Example 1 in that the rinsing reaction was performed with a fluorosilane solution at a rate of 5 mL / min.

[0065] Comparative Example 2

[0066] Comparative Example 2 differs from Example 1 in that the rinsing reaction was performed with a fluorosilane solution at a rate of 7 mL / min.

[0067] Comparative Example 3

[0068] Comparative Example 3 differs from Example 1 in that the rinsing reaction was performed with a fluorosilane solution at a rate of 8 mL / min.

[0069] Comparative Example 4

[0070] Comparative Example 4 differs from Example 2 in that the rinsing reaction was performed with a fluorosilane solution at a rate of 12 mL / min.

[0071] Comparative Example 5

[0072] Comparative Example 5 differs from Example 2 in that the rinsing reaction was performed with a fluorosilane solution at a rate of 13 mL / min.

[0073] Comparative Example 6

[0074] Comparative Example 6 differs from Example 2 in that the rinse reaction is performed with a fluoro-silane solution at 15 mL / min.

[0075] Comparative Example 7

[0076] Comparative Example 7 differs from Example 3 in that the rinse reaction is performed with a fluoro-silane solution at 10 mL / min.

[0077] Comparative Example 8

[0078] Comparative Example 8 differs from Example 3 in that the rinse reaction is performed with a fluoro-silane solution at 12 mL / min.

[0079] Comparative Example 9

[0080] Comparative Example 9 differs from Example 1 in that a silicon wafer (4-inch, p-type, 500 μm thick) is used instead of a silicon carbide wafer.

[0081] Comparative Example 10

[0082] Comparative Example 10 differs from Example 2 in that a silicon wafer (4-inch, p-type, 500 μm thick) is used instead of a silicon carbide wafer.

[0083] Comparative Example 11

[0084] Comparative Example 11 differs from Example 3 in that a silicon wafer (4-inch, p-type, 500 μm thick) is used instead of a silicon carbide wafer.

[0085] Comparative Example 12

[0086] Comparative Example 12 differs from Example 1 in that an alkylsilane is used instead of perfluorooctyltriethoxysilane.

[0087] Each experimental condition is repeated at least 3 times to reduce experimental error. During etching, the etching temperature and time are strictly controlled, and the stirring speed of the solution in the etching tank is 100 r / min to ensure consistency in each experiment. When measuring the surface roughness and contact angle, multiple measurement points are selected, and the average value is taken as the final result. The experimental equipment, such as the surface roughness meter and the contact angle measuring instrument, is calibrated regularly to ensure the accuracy of the measurement data, with a calibration period of once a week. The surface roughness Ra value of the pretreated wafer in all examples and comparative examples is measured using a surface roughness meter to ensure that it is within the target range (with an error of no more than ±0.1 nm).

[0088] The quantitative relationship between the surface roughness Ra and the fluoro-silane solution flow rate Q in Examples 1 to 4 and Comparative Examples 1 to 8 is calculated, and the specific results are shown in Table 1.

[0089] Table 1

[0090]

[0091] The surface morphology and contact angle of the surface modified wafers prepared in all examples and comparative examples were characterized, and the surface metal ion adsorption amount of the surface modified wafers was tested by wet etching-IPC-MS method, and the specific results are shown in Table 2.

[0092] Table 2

[0093]

[0094] According to Table 1 and Table 2, in the preparation method provided by the application, the surface roughness Ra of the pretreated silicon carbide wafer and the flow rate Q of the fluorine-containing silane solution show a nonlinear relationship of "first increasing and then stable", and when the surface roughness Ra and the matched flow rate Q of the fluorine-containing silane solution satisfy a specific quantity relationship, the contact angle of the surface modified wafer is larger, the surface uniformity is good, and the surface metal ion adsorption amount is significantly reduced, while the flow rate is too high or too low, which will lead to the decline of the surface modification quality, and the surface metal ion adsorption amount is still too high.

[0095] The technical features of the above-described examples can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above-described examples are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0096] The above-described examples only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A method of surface treatment of a silicon carbide wafer, characterized by, comprising the following steps: The silicon carbide wafer is pretreated by an acid solution, so that the surface roughness of the pretreated silicon carbide wafer is Ra, unit: nm; The pretreated silicon carbide wafer is rinsed with a fluorine-containing silane solution, wherein the flow rate Q of the fluorine-containing silane solution is -4.5Ra 2 + 16.2Ra + n, n = -1.7 to -1.5, in units of mL / min, with a goodness of fit ≥ 0.

95.

2. The surface treatment method of a silicon carbide wafer according to claim 1, wherein The surface roughness Ra of the pretreated silicon carbide wafer is 0.5nm to 2.0nm.

3. The surface treatment method of a silicon carbide wafer according to claim 1, wherein The mass concentration of fluorine-containing silane in the fluorine-containing silane solution is 0.1% to 1%.

4. The surface treatment method of a silicon carbide wafer according to claim 1 or claim 3, characterized by, The fluorine-containing silane solution is selected from at least one of perfluorooctyltriethoxysilane solution and tridecafluorooctyltriethoxysilane solution.

5. The surface treatment method of a silicon carbide wafer according to claim 1, wherein The temperature of the rinsing reaction is 20℃ to 50℃, and the time is 30s to 120s.

6. The surface treatment method of a silicon carbide wafer according to claim 1, wherein The acid solution is selected from a hydrofluoric acid solution, and the mass concentration of hydrofluoric acid in the hydrofluoric acid solution is 5% to 8%.

7. The surface treatment method of a silicon carbide wafer according to Claim 1, wherein The pretreatment temperature is 20℃ to 30℃, and the time is 10s to 60s.

8. The surface treatment method of a silicon carbide wafer according to claim 1, wherein The silicon carbide wafer after the rinsing reaction is subjected to photocuring treatment, and the wavelength of the photocuring treatment is 10nm to 400nm, and the time is 30min to 45min.

9. A surface-modified silicon carbide wafer, characterized by, The surface-modified silicon carbide wafer is prepared by the surface treatment method of the silicon carbide wafer according to any one of claims 1 to 8, and the contact angle of the surface-modified silicon carbide wafer is greater than 110°.

10. Use of the surface-modified silicon carbide wafer according to claim 9 in the preparation of a semiconductor device.

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